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path: root/drivers/i2c/busses/i2c-i801.c
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2016-04-12i2c: i801: Add runtime PM support with autosuspendJarkko Nikula
Allow runtime PM so that PM and PCI core can put the device into low-power state when idle and resume it back when needed in those platforms that support PM for i801 device. Enable also autosuspend with 1 second delay in order to not needlessly toggle power state on and off if there are multiple transactions during short time. Device is resumed at the beginning of bus access and marked idle ready for autosuspend at the end of it. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-04-12i2c: i801: Convert to struct dev_pm_ops for suspend/resumeJarkko Nikula
Stop using legacy PCI PM support and convert to standard dev_pm_ops. This provides more straightforward path to add runtime PM. While at it remove explicit PCI power state control and configuration space save/restore as the PCI core does it. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-03-22Merge branch 'i2c/for-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux Pull i2c updates from Wolfram Sang: "Mostly usual driver updates and improvements. The changelog should give an idea. Standing out is the i2c-qup driver with lots of new capabilities and we also have now an i2c-demuxer. I'd especially like to welcome Peter Rosin as the i2c-mux maintainer. He has an interesting series for muxes in the queue and agreed to look after this part of the subsystem. Thank you, Peter, and welcome again! The octeon changes were applied pretty recently before the merge window. I am aware. They are the first (and relatively simple) patches of a larger overhaul to this driver. In case something goes wrong with them, they are easy to fix (or revert). The advantage I see is that they are out of the way, and I can concentrate on the next block of patches. I really would like to apply the overhaul in smaller batches to avoid regressions. And waiting a cycle for the introductory patches seemed too much of a delay for me" * 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (39 commits) i2c: octeon: Support I2C_M_RECV_LEN i2c: octeon: Cleanup resource allocation code i2c: octeon: Cleanup i2c-octeon driver MAINTAINERS: add Peter Rosin as i2c mux maintainer dt-bindings: i2c: Spelling s/propoerty/property/ i2c: immediately mark ourselves as registered i2c: i801: sort IDs alphabetically MAINTAINERS: Mika and me are designated reviewers for I2C DESIGNWARE i2c: octeon: Cleanup kerneldoc comments i2c: do not use internal data from driver core i2c: cadence: Fix the kernel-doc warnings i2c: imx: remove extra spaces. i2c: rcar: don't open code of_device_get_match_data() i2c: qup: Fix fifo handling after adding V2 support i2c: xiic: Implement power management i2c: piix4: Pre-shift the port number i2c: piix4: Always use the same type for port i2c: piix4: Support alternative port selection register i2c: tegra: don't open code of_device_get_match_data() i2c: riic, sh_mobile, rcar: Use ARCH_RENESAS ...
2016-03-12i2c: i801: sort IDs alphabeticallyAndy Shevchenko
Sort the list to have a faster search for a certain PCI ID. There is no functional change. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-02-18i2c: i801: Adding Intel Lewisburg support for iTCOAlexandra Yates
Starting from Intel Sunrisepoint (Skylake PCH) the iTCO watchdog resources have been moved to reside under the i801 SMBus host controller whereas previously they were under the LPC device. This patch adds Intel lewisburg SMBus support for iTCO device. It allows to load watchdog dynamically when the hardware is present. Fixes: cdc5a3110e7c ("i2c: i801: add Intel Lewisburg device IDs") Reviewed-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Alexandra Yates <alexandra.yates@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Cc: stable@kernel.org
2015-11-20i2c: i801: add Intel Lewisburg device IDsAlexandra Yates
Adding Intel codename Lewisburg platform device IDs for SMBus. Signed-off-by: Alexandra Yates <alexandra.yates@linux.intel.com> Reviewed-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-10-25i2c: add ACPI support for I2C mux portsDustin Byford
Although I2C mux devices are easily enumerated using ACPI (_HID/_CID or device property compatible string match), enumerating I2C client devices connected through an I2C mux needs a little extra work. This change implements a method for describing an I2C device hierarchy that includes mux devices by using an ACPI Device() for each mux channel along with an _ADR to set the channel number for the device. See Documentation/acpi/i2c-muxes.txt for a simple example. To make this work the ismt, i801, and designware pci/platform devs now share an ACPI companion with their I2C adapter dev similar to how it's done in OF. This is done on the assumption that power management functions will not be called directly on the I2C dev that is sharing the ACPI node. Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Dustin Byford <dustin@cumulusnetworks.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-10-23i2c: i801: Add support for Intel BroxtonJarkko Nikula
This patch adds the SMBUS PCI ID of Intel Broxton. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-10-23i2c: i801: Add support for Intel DNVMika Westerberg
Intel DNV SoC has the same legacy SMBus host controller than Intel Sunrisepoint PCH. It also has same iTCO watchdog on the bus. Add DNV PCI ID to the list of supported devices. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-11i2c: i801: Create iTCO device on newer Intel PCHsMika Westerberg
Starting from Intel Sunrisepoint (Skylake PCH) the iTCO watchdog resources have been moved to reside under the i801 SMBus host controller whereas previously they were under the LPC device. In order to support the iTCO watchdog on newer PCHs we need to create the platform device here in the SMBus driver and pass all known resources using platform data. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2015-03-09i2c: i801: Use managed pcim_* PCI device initialization and reservationJarkko Nikula
Simplifies the code a bit and makes easier to disable PCI device on driver detach by removing the pcim_pin_device() call in the future if needed. Reason why i2c-i801.c doesn't ever call pci_disable_device() was because it made some systems to hang during power-off. See commit d6fcb3b9cf77 ("[PATCH] i2c-i801.c: don't pci_disable_device() after it was just enabled") and http://marc.info/?l=linux-kernel&m=115160053309535&w=2 Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reviewed-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-03-09i2c: i801: Remove pci_enable_device() call from i801_resume()Jarkko Nikula
Since pci_disable_device() is not called from i801_suspend() and power state is set already it means that subsequent pci_enable_device() calls do practically nothing but monotonically increase struct pci_dev enable_cnt. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reviewed-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-03-09i2c: i801: Use managed devm_* memory and irq allocationJarkko Nikula
This simplifies the error and remove paths. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reviewed-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-03-09i2c: i801: Remove i801_driver forward declarationJarkko Nikula
struct pci_driver i801_driver forward declaration is needed only for accessing the name field. Remove it and use dev_driver_string() instead. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reviewed-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-03-09i2c: i801: Don't break user-visible stringsJarkko Nikula
It makes more difficult to grep these error prints from sources if they are split to multiple source lines. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reviewed-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-11-12i2c: i801: Add DeviceIDs for SunrisePoint LPDevin Ryles
Signed-off-by: Devin Ryles <devin.ryles@intel.com> Reviewed-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-11-12i2c: i801: Drop useless debug messageJean Delvare
Don't log the host status register value in i801_isr(), it has very little value and fills up the log when debugging is enabled. Signed-off-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-11-12i2c: i801: Check if interrupts are disabledJean Delvare
There is a control bit in the PCI configuration space which disables interrupts. If this bit is set, the driver should not try to make use of interrupts, it won't receive any. Signed-off-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-11-12i2c: i801: Fallback to polling if request_irq() failsJean Delvare
The i2c-i801 driver can work without interrupts, so there is no reason to make a request_irq failure fatal. Instead we can simply fallback to polling. Signed-off-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-11-12i2c: i801: Use wait_event_timeout to wait for interruptsJean Delvare
Some systems have been reported to have trouble with interrupts. Use wait_event_timeout() instead of wait_event() so we don't get stuck in that case, and log the problem. Signed-off-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-11-07i2c: remove FSF addressWolfram Sang
We have a central copy of the GPL for that. Some addresses were already outdated. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
2014-10-16i2c: i801: Add Device IDs for Intel Sunrise Point PCHjames.d.ralston@intel.com
This patch adds the I2C/SMBus Device IDs for the Intel Sunrise Point PCH. Signed-off-by: James Ralston <james.d.ralston@intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-08-19i2c: i801: Add PCI ID for Intel BraswellAlan Cox
The SMBus host controller is the same as used in Baytrail so add the new PCI ID to the driver's list of supported IDs. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-07-17i2c: i801: Add device ID for Intel Wildcat Point PCHJean Delvare
Signed-off-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-07-17i2c: i801: Fix the alignment of the device tableJean Delvare
A long name broke the alignment, shift the columns a bit to fix it and make the table look nice again. While we're here, switch to the standard comment style to make checkpatch happy, and use tabs instead of spaces for column alignment. Signed-off-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-03-13i2c: remove DEFINE_PCI_DEVICE_TABLE macroJingoo Han
Don't use DEFINE_PCI_DEVICE_TABLE macro, because this macro is not preferred. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-03-09i2c: i801: enable Intel BayTrail SMBUSChew, Kean ho
Add Device ID of Intel BayTrail SMBus Controller. Signed-off-by: Chew, Kean ho <kean.ho.chew@intel.com> Signed-off-by: Chew, Chiau Ee <chiau.ee.chew@intel.com> Reviewed-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-01-29Update Jean Delvare's e-mail addressJean Delvare
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2013-11-14i2c: i801: Add Device IDs for Intel Wildcat Point-LP PCHJames Ralston
This patch adds the SMBus Device IDs for the Intel Wildcat Point-LP PCH. Signed-off-by: James Ralston <james.d.ralston@intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-08-23i2c: move OF helpers into the coreWolfram Sang
I2C of helpers used to live in of_i2c.c but experience (from SPI) shows that it is much cleaner to have this in the core. This also removes a circular dependency between the helpers and the core, and so we can finally register child nodes in the core instead of doing this manually in each driver. So, fix the drivers and documentation, too. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-20i2c: i801: SMBus patch for Intel Coleto Creek DeviceIDsSeth Heasley
This patch adds the i801 SMBus Controller DeviceIDs for the Intel Coleto Creek PCH. Signed-off-by: Seth Heasley <seth.heasley@intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-05-17i2c: i801: Document feature bits in modinfoJean Delvare
Duplicate the feature bits documentation in modinfo, as not every user will read the driver's source code or documentation file. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-02-22i2c: Remove unneeded xxx_set_drvdata(..., NULL) callsDoug Anderson
There is simply no reason to be manually setting the private driver data to NULL in the remove/fail to probe cases. This is just extra cruft code that can be removed. A few notes: * Nothing relies on drvdata being set to NULL. * The __device_release_driver() function eventually calls dev_set_drvdata(dev, NULL) anyway, so there's no need to do it twice. * I verified that there were no cases where xxx_get_drvdata() was being called in these drivers and checking for / relying on the NULL return value. This could be cleaned up kernel-wide but for now just take the baby step and remove from the i2c subsystem. Reported-by: Wolfram Sang <wsa@the-dreams.de> Reported-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Doug Anderson <dianders@chromium.org> Reviewed-by: Jean Delvare <khali@linux-fr.org> Acked-by: Peter Korsgaard <jacmet@sunsite.dk> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Marek Vasut <marex@denx.de> Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>
2013-02-15i2c: i801: Add Device IDs for Intel Wellsburg PCHJames Ralston
This patch adds the SMBus Device IDs for the Intel Wellsburg PCH Signed-off-by: James Ralston <james.d.ralston@intel.com> Reviewed-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>
2013-02-08i2c: i801: SMBus patch for Intel Avoton DeviceIDsSeth Heasley
This patch adds the PCU SMBus DeviceID for the Intel Avoton SOC. Signed-off-by: Seth Heasley <seth.heasley@intel.com> Reviewed-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-12-22i2c: remove __dev* attributes from subsystemBill Pemberton
CONFIG_HOTPLUG is going away as an option. As result the __dev* markings will be going away. Remove use of __devinit, __devexit_p, __devinitdata, __devinitconst, and __devexit. Signed-off-by: Bill Pemberton <wfp5p@virginia.edu> Acked-by: Peter Korsgaard <peter.korsgaard@barco.com> (for ocores and mux-gpio) Acked-by: Havard Skinnemoen <hskinnemoen@gmail.com> (for i2c-gpio) Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> (for puf3) Acked-by: Barry Song <baohua.song@csr.com> (for sirf) Reviewed-by: Jean Delvare <khali@linux-fr.org> [wsa: Fixed "foo* bar" flaws while we are here] Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-12-16i2c-i801: Enable interrupts for all post-ICH5 chipsJean Delvare
I did not receive a single bug report after interrupt support was added for a limited number of chips. So I'd say the code is good and should be enabled for all supported chips, that is: ICH5 and later. Signed-off-by: Jean Delvare <khali@linux-fr.org> Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
2012-12-16i2c-i801: Add device tree supportThierry Reding
Add support for probing slave devices parsed from the device tree. Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-10-28i2c-i801: Fix commentJean Delvare
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-10-28i2c-i801: Simplify dependency towards GPIOLIBJean Delvare
Arbitrarily selecting GPIOLIB causes trouble on some architectures, so don't do that. Instead, just make the optional multiplexing code depend on CONFIG_I2C_MUX_GPIO instead of CONFIG_I2C_MUX for now. We can revisit if the i2c-i801 driver ever supports other multiplexing flavors. Also make that optional code depend on DMI, as it won't do anything without that. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Fengguang Wu <fengguang.wu@intel.com>
2012-10-05i2c-i801: Let i2c-mux-gpio find the GPIO chipJean Delvare
Now that i2c-mux-gpio is able to find the GPIO chip by itself, we can delegate this task. The great thing here is that i2c-mux-gpio can defer device probing until the gpio chip is available, so we no longer depend on the module loading order. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-10-05i2c-i801: Support SMBus multiplexing on Asus Z8 seriesJean Delvare
Add support for SMBus multiplexing on Asus Z8 motherboard series. On these boards, the memory slots are behind a GPIO-controlled I2C multiplexer. Models with 6 or 12 memory slots have 2 segments behind the multiplexer, while models with 18 memory slots have 3 such segments. On these boards, only the memory slots are behind the multiplexer, so it is possible to keep the autodetection mechanism. The code is generic enough so it could work on other boards as long as the multiplexer is controlled by GPIO pins. For other forms of multiplexing (for example using an I2C device) additional code will be needed. Thanks to Asus for providing a board to develop and test this feature, as well as all the technical information required. At the moment, the GPIO driver must be loaded before the i2c-i801 driver, but I hope to solve this soon, using deferred probing on the i2c-mux-gpio side. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-09-10i2c-i801: Add Device IDs for Intel Lynx Point-LP PCHJames Ralston
Add the SMBus Device IDs for the Intel Lynx Point-LP PCH. Signed-off-by: James Ralston <james.d.ralston@intel.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24i2c-i801: Enable IRQ for byte_by_byte transactionsDaniel Kurtz
Byte-by-byte transactions are used primarily for accessing I2C devices with an SMBus controller. For these transactions, for each byte that is read or written, the SMBus controller generates a BYTE_DONE IRQ. The isr reads/writes the next byte, and clears the IRQ flag to start the next byte. On the penultimate IRQ, the isr also sets the LAST_BYTE flag. There is no locking around the cmd/len/count/data variables, since the I2C adapter lock ensures there is never multiple simultaneous transactions for the same device, and the driver thread never accesses these variables while interrupts might be occurring. The end result is faster I2C block read and write transactions. Note: This patch has only been tested and verified by doing I2C read and write block transfers on Cougar Point 6 Series PCH, as well as I2C read block transfers on ICH5. Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24i2c-i801: Enable interrupts on ICH5/7/8/9/10Jean Delvare
Enable interrupts on more devices. ICH5, ICH7(-M) and ICH10 have been tested to work OK. ICH8 and ICH9 are expected to work just fine as they are very close to ICH7 and ICH10. Ultimately we want to enable this feature on at least every device since the ICH5, but for now we limit the exposure. We'll enable it for other devices if we don't get negative feedback. As a bonus, let the user know when interrupts are used. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Daniel Kurtz <djkurtz@chromium.org>
2012-07-24i2c-i801: Enable IRQ for SMBus transactionsDaniel Kurtz
Add a new 'feature' to i2c-i801 to enable using PCI interrupts. When the feature is enabled, then an isr is installed for the device's PCI IRQ. An I2C/SMBus transaction is always terminated by one of the following interrupt sources: FAILED, BUS_ERR, DEV_ERR, or on success: INTR. When the isr fires for one of these cases, it sets the ->status variable and wakes up the waitq. The waitq then saves off the status code, and clears ->status (in preparation for some future transaction). The SMBus controller generates an INTR irq at the end of each transaction where INTREN was set in the HST_CNT register. No locking is needed around accesses to priv->status since all writes to it are serialized: it is only ever set once in the isr at the end of a transaction, and cleared while no interrupts can occur. In addition, the I2C adapter lock guarantees that entire I2C transactions for a single adapter are always serialized. For this patch, the INTREN bit is set only for SMBus block, byte and word transactions, but not for I2C reads or writes. The use of the DS (BYTE_DONE) interrupt with byte-by-byte I2C transactions is implemented in a subsequent patch. The interrupt feature has only been enabled for COUGARPOINT hardware. In addition, it is disabled if SMBus is using the SMI# interrupt. Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24i2c-i801: Consolidate pollingJean Delvare
(Based on earlier work by Daniel Kurtz.) Come up with a consistent, driver-wide strategy for event polling. For intermediate steps of byte-by-byte block transactions, check for BYTE_DONE or any error flag being set. At the end of every transaction (regardless of PEC being used), check for both BUSY being cleared and INTR or any error flag being set. This ensures proper action for all transaction types. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Daniel Kurtz <djkurtz@chromium.org>
2012-07-24i2c-i801: Drop ENABLE_INT9Daniel Kurtz
Later patches enable interrupts. This preliminary patch removes the older unsupported ENABLE_INT9 flag. Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24i2c-i801: Rename some SMBHSTCNT bit constantsDaniel Kurtz
Rename the SMBHSTCNT register bit access constants to match the style of other register bits. Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24i2c-i801: Check and return errors during byte-by-byte transfersDaniel Kurtz
If an error is detected in the polling loop, abort the transaction and return an error code. * DEV_ERR is set if the device does not respond with an acknowledge, and the SMBus controller times out (minimum 25ms). * BUS_ERR is set if a bus arbitration collision is detected. In other words, when the SMBus controller tries to generate a START condition, but detects that the SMBDATA is being held low, usually by another SMBus/I2C master. * FAILED is only set if a transaction is stopped by software (using the SMBHSTCNT KILL bit). Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Signed-off-by: Jean Delvare <khali@linux-fr.org>